Veneer and plywood properties of yemane (Gmelina arborea Roxb.) from 3-, 5-, and 7-year-old plantation trees

ABSTRACT Young (3-, 5- and 7-year-old) yemane (Gmelina arborea Roxb.) trees from an industrial tree plantation in Mindanao, Philippines, were studied for their suitability into veneer and plywood production. For each tree, a 4.5-meter log was cut into three 1.5-meter billets for peeling into 0.85-, 2.20- and 2.80-mm veneer thicknesses using a spindleless lathe. Veneer quality was evaluated based on thickness, frequency and depth of lathe checks on the samples. Ten replicates of 3-ply 4.5 mm plywood bonded with phenol formaldehyde were made per age level to determine conformance to standard. Results showed that veneer thickness was higher than the target by 3–22%. Mean frequency of lathe checks ranged from 1 to 10 per 25 mm veneer length, while mean depth ranged from 15 to 60%. The bond strength quality test showed that despite young age, yemane plywood passed the requirement of the PNS ISO 12466-2:2016.